#include<stdio.h>
#include<conio.h>
#include<math.h>
int main()
{
	int n;
	float s=1;
	printf("Nhap so n = ");
	scanf("%d",&n);
	for(int i = 1; i<=n;i++){
		s=s+(1/(2*i));
	}
	
	printf("S= %0.1f",s);
	getch();
}
